user_list用户表、project_list项目表、user_project_mid用户-项目关联表

//建立关联关系
// 与ProjectList存在多对多关系，使用belongsToMany() 中间表为UserProjectMid
        app.model.UserList.belongsToMany(app.model.ProjectList, {
            through: app.model.UserProjectMid,
            foreignKey: 'userName',   //关联表的userName
            sourceKey:'userName',     //通过ProjectList表的userName与关联表关联，如果不设置默认与主键关联
            otherKey: 'projectId'
        });
// 与UserList存在多对多关系，使用belongsToMany() 中间表为UserProjectMid
        app.model.ProjectList.belongsToMany(app.model.UserList, {
            through: app.model.UserProjectMid,
            foreignKey: 'projectId',    //关联表的userName
            otherKey: 'userName'
        });

//查询当前用户下的所有项目
async getProject(params) {
        const { app } = this;
        let { userName } = params
        let data = await app.model.ProjectList.findAll({
            include: [{
                model: app.model.UserList,
                where: {
                    userName  //筛选当前用户
                },
                attributes: []    //舍弃用户信息的内容
            }]
        })

        return data

    }

//获取项目所有成员
    async getProjectTeam(params) {
        const { app } = this;
        let { projectId } = params
        let data = await app.model.UserList.findAll({
            attributes: [Sequelize.col('project_lists.user_project_mid.level'),'avatar','nickname','userName'],  //数据打平后要输出的zi段 
            include: [{        //关联查询选项
                model: app.model.ProjectList,
                where: {
                    id:projectId
                },
                through: { attributes: [] },   //筛选中间表字段
                attributes: []    //筛选关联表字段
            }],
            raw: true,    //数据打平属性
        })

        return data
    }